Basalt nanosheet and preparation method thereof

Abstract

The present application relates to basalt nanomaterial technical field, aiming at the uneven product performance of existing modified basalt sheet, and the problem of instability and long effect, a kind of basalt nanometer sheet and its preparation method are disclosed, the basalt nanometer sheet includes modified basalt scale and perovskite, and the modified basalt scale is connected with the perovskite by coordination bonding;The dosage ratio of the modified basalt scale and the perovskite is 1.2-1.5:0.5-0.85 by mass.The modified basalt scale is first amidated and modified, then combined with perovskite for compounding, the coordination ion in perovskite is combined with amido group by coordination, under the action of dipole, the coordination effect of amido group and lead ion is obviously enhanced, the defect state density caused by basalt and other material modification composite is reduced, so that the basalt material performance is more stable controllable and long effect.

Description

Technical Field

[0001] This invention relates to the field of basalt nanomaterials technology, and more specifically, to a basalt nanosheet and its preparation method. Background Technology

[0002] Basalt fiber is an inorganic, environmentally friendly, high-performance fiber material, mainly composed of oxides such as silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, iron oxide, and titanium dioxide. It is produced by melting basalt ore at high temperatures and then drawing it into fibers. It has silicates similar to those found in natural minerals and is biodegradable after disposal. As one of my country's four major fiber industries, basalt fiber has achieved industrialized production and application, commonly found in fiber-reinforced composite materials, friction materials, shipbuilding materials, thermal insulation materials, the automotive industry, high-temperature filter fabrics, and protective materials.

[0003] With the rapid development of electronics and other technologies, the application of basalt fiber materials is becoming increasingly widespread, leading to higher demands on material morphology and other aspects. For example, patent CN114477199A provides a method for preparing basalt nanosheets, which, through sequential surface etching, deep etching, dispersion, and pulverization, can produce basalt nanosheets with higher precision. Furthermore, patent CN115044079A provides a composite insulating film doped with aramid nanofibers and basalt nanosheets, and its preparation method. This method combines aramid nanofibers with basalt nanosheets through doping, thereby endowing the basalt nanosheets with higher strength and temperature resistance. However, in the above-mentioned insulating films, when aramid nanofibers are doped with basalt nanosheets, the controllability of the porosity bonding between the aramid nanofibers and basalt nanosheets is low, resulting in uneven or insufficient doping and inconsistent product performance.

[0004] Based on the above, there is a need for a high-performance basalt nanosheet material with stable product performance. Summary of the Invention

[0005] The technical problem to be solved by this invention:

[0006] In existing basalt sheet materials, to improve the material properties of basalt sheets or to endow them with the characteristics required for specific applications, other materials with modifying functions are usually incorporated into the basalt sheets for composite processing, thereby improving the overall performance of the basalt sheets according to needs. However, in modification treatments aimed at improving the hardness or durability of basalt sheets, the performance of basalt sheet products is inconsistent, unstable, and not long-lasting.

[0007] The technical solution adopted in this invention is as follows:

[0008] This invention provides a basalt nanosheet comprising modified basalt flakes and perovskite, wherein the modified basalt flakes and the perovskite are connected by coordination bonding; the ratio of the modified basalt flakes to the perovskite by mass is 1.2-1.5:0.5-0.85.

[0009] Preferably, the thickness of the basalt flakes is 3-20 μm.

[0010] Preferably, its thickness is 20-45 nm.

[0011] The present invention also provides a method for preparing the above-mentioned basalt nanosheets, comprising the following steps:

[0012] (1) Preparation of modified basalt flakes;

[0013] (2) Preparation of perovskite precursor solution;

[0014] (3) Add the modified basalt flakes to the perovskite precursor solution, heat to 50-65℃ for reaction, then cool to 25-35℃ for reaction, pulverize, and dry to obtain the basalt nanosheets.

[0015] Preferably, in step (1), the method for preparing modified basalt flakes includes the following steps: taking cleaned basalt fiber flakes, adding them to a 1.5-2.8% volume fraction of amide-silane coupling agent-ethanol solution, adding a catalyst, stirring and reacting, filtering and drying to obtain the modified basalt flakes.

[0016] Preferably, the preparation method of the amide-containing silane coupling agent includes the following steps: taking an aminosilane coupling agent and xylene, mixing them evenly, placing them in a reaction at 5-10℃, and adding glacial acetic acid dropwise during the reaction; after the reaction is completed, removing impurities by distillation to obtain the amide-containing silane coupling agent.

[0017] Preferably, the mass ratio of aminosilane coupling agent to xylene is 1:2.5-3.

[0018] Preferably, at the start of the reaction, glacial acetic acid is added dropwise at a uniform rate of 0.5-1.5 mL / min, and the total amount of glacial acetic acid added is equal in mass to that of the aminosilane coupling agent.

[0019] Preferably, in step (2), the method for preparing the perovskite precursor solution includes the following steps: taking perovskite, adding it to 1.5-3 times its volume of organic solvent, and ultrasonically dispersing it to obtain the perovskite precursor solution.

[0020] Preferably, in step (3), the reaction time at 50-65℃ is 1-2.5h, and the reaction time at 25-35℃ is 0.5-1.25h.

[0021] The beneficial effects of this invention are as follows:

[0022] The basalt nanosheets of this invention first undergo amide modification of basalt flakes, and then are combined with perovskite for compounding. Through coordination bonding between the coordinating ions in the perovskite and the amide groups, the coordination effect between the amide groups and lead ions is significantly enhanced under dipole action, reducing the defect state density caused by the modification and compounding of basalt with other materials, making the basalt material properties more stable, controllable, and long-lasting. Furthermore, during coordination bonding, through appropriate heating reaction, calcium ions in the perovskite achieve covalent bonding with basalt flakes to form silicon-oxygen-calcium bonds, thereby improving the strength of the basalt material and maintaining long-term stability in harsh environments. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0024] This invention provides a method for preparing basalt nanosheets, comprising the following steps:

[0025] (1) Take an appropriate amount of basalt flakes, place them in ethanol, and let the ethanol completely submerge the basalt flakes. Stir, filter and dry to obtain basalt flakes with a layer thickness of about 3-20 μm to be treated. Separately, take an amide-containing silane coupling agent, add ethanol, and prepare an amide-containing silane coupling agent solution with a volume fraction of 1.5-2.8%. Add the basalt flakes to be treated and the catalyst, stir to react, filter and dry to obtain amide-containing basalt flakes, which can be used as modified basalt flakes.

[0026] (2) Take an appropriate amount of perovskite and add it to 1.5-3 times the volume of organic solvent. Disperse it ultrasonically for 0.5-1.2 hours to obtain a perovskite precursor solution.

[0027] (3) Take amide-based basalt flakes and add them to the perovskite precursor solution. Control the mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution to be 1.2-1.5:0.5-0.85. First, apply an external electric field to heat to 50-65℃ and react for 1-2.5h. Then remove the electric field and cool to 25-35℃ and react for 0.5-1.25h. After the reaction is completed, ultrasonically pulverize, let stand to separate into layers, remove the clear layer, and place in a 0.05-0.1MPa vacuum drying oven to dry for 20-35h to obtain basalt nanosheets with a thickness of about 20-45nm.

[0028] In this invention, amide-based basalt flakes combine with overcoordinated lead ions in perovskite. Under an applied electric field, the coordination effect between the amide group and lead ions is significantly enhanced through dipole interaction, reducing the defect state density caused by the modification and composite of basalt with other materials. This makes the performance of basalt nanosheet products more stable, controllable, and long-lasting.

[0029] The preparation method of the amide-silane coupling agent in this invention includes the following steps:

[0030] Take an aminosilane coupling agent, add 2.5-3 times its mass of xylene, mix well, and place in a low temperature environment of 5-10℃ to react. After the reaction starts, add glacial acetic acid of the same mass as the aminosilane coupling agent dropwise at a uniform rate of 0.5-1.5 mL / min. After the dropwise addition is completed, continue stirring the reaction for 8-10 h. Distill to remove impurities to obtain an amide-containing silane coupling agent.

[0031] Among them, the aminosilane coupling agent can be selected from common and universal amino-containing silane coupling agents such as dimethyldimethoxysilane, isopropyltrimethoxysilane, dimethylaminosilane, and butylaminosilane.

[0032] Example 1

[0033] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0034] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-basalt flakes, which are stored for later use.

[0035] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0036] With a mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution of 1.2:0.7, the amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ under an external electric field and reacted for 1.75h, then the electric field was removed and the temperature was lowered to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt nanosheets with a thickness of approximately 30nm.

[0037] Example 2

[0038] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0039] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of approximately 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, with the mass of the basalt flakes being twice the mass of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-based basalt flakes, which are stored for later use.

[0040] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0041] With a mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution of 1.2:0.7, the amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ under an external electric field and reacted for 1.75h, then the electric field was removed and the temperature was lowered to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt nanosheets with a thickness of approximately 30nm.

[0042] Example 3

[0043] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0044] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of approximately 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, with the mass of the amide-silane coupling agent being twice the mass of the basalt flakes to be treated. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-based basalt flakes, which are stored for later use.

[0045] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0046] With a mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution of 1.2:0.7, the amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ under an external electric field and reacted for 1.75h, then the electric field was removed and the temperature was lowered to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt nanosheets with a thickness of approximately 30nm.

[0047] Example 4

[0048] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0049] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-basalt flakes, which are stored for later use.

[0050] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0051] With a mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution of 1.5:0.55, amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ under an external electric field and reacted for 1.75h, then the electric field was removed and the temperature was lowered to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt nanosheets with a thickness of approximately 30nm.

[0052] Example 5

[0053] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0054] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-basalt flakes, which are stored for later use.

[0055] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0056] With a mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution of 1.2:0.83, amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ under an external electric field and reacted for 1.75h, then the electric field was removed and the temperature was lowered to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt nanosheets with a thickness of approximately 30nm.

[0057] Example 6

[0058] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0059] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-basalt flakes, which are stored for later use.

[0060] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0061] The amide-based basalt flakes were added to the perovskite precursor solution at a mass ratio of 1.2:0.7. The solution was first heated to 50°C with an external electric field and reacted for 1 hour, then cooled to 33°C with the electric field removed and reacted for 1.2 hours. After the reaction was completed, the solution was ultrasonically treated for 30 hours to obtain basalt nanosheets with a thickness of approximately 30 nm.

[0062] Example 7

[0063] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0064] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-basalt flakes, which are stored for later use.

[0065] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0066] With a mass ratio of amide-based basalt flakes to perovskite in the perovskite precursor solution of 1.2:0.7, amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 65°C with an external electric field and reacted for 2.3 h, then the electric field was removed and the temperature was lowered to 30°C and reacted for 0.85 h. After the reaction was completed, the solution was ultrasonically treated for 30 h to obtain basalt nanosheets with a thickness of approximately 30 nm.

[0067] Comparative Example 1

[0068] Basalt flakes were placed in ethanol until they were completely submerged. The mixture was stirred for 15 minutes, filtered, and dried to remove impurities from the surface of the basalt flakes and to form a large number of porous structures. Basalt flakes with a layer thickness of about 15 μm were obtained and stored for later use.

[0069] Take perovskite, add 2.5 times its volume of dimethylformamide, and ultrasonically disperse for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0070] With a mass ratio of basalt flakes to perovskite in the perovskite precursor solution of 1.2:0.7, amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ and reacted for 1.75h, then cooled to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt sheets.

[0071] Comparative Example 2

[0072] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0073] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another dimethyldimethoxysilane and add it to ethanol to prepare a 2.2% (v / v) dimethyldimethoxysilane-ethanol solution. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the dimethyldimethoxysilane. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 h, filter and dry to obtain aminobasalt flakes, which are stored for later use.

[0074] Take another perovskite, add 2.5 times its volume of dimethylformamide, and sonicate for 1 hour to obtain a perovskite precursor solution, which is then stored for later use.

[0075] With a mass ratio of 1.2:0.7 between amino-based basalt flakes and perovskite in the perovskite precursor solution, the amide-based basalt flakes were added to the perovskite precursor solution. The solution was first heated to 60±2℃ and reacted for 1.75h, then cooled to 30±2℃ and reacted for 0.85h. After the reaction was completed, the solution was ultrasonically treated for 30h to obtain basalt sheets.

[0076] Comparative Example 3

[0077] Take 1 part by mass of dimethyldimethoxysilane, add 2.5 parts by mass of xylene, stir and mix well, and place in a low temperature oven at 7±2℃ to react. At the beginning of the reaction, add 1 part by mass of glacial acetic acid dropwise at a uniform rate, and control the total dropwise time to about 2 hours. After the dropwise addition is completed, continue stirring and reacting for 8 hours. Finally, distill to remove excess acid anhydride and xylene to obtain amide silane coupling agent, which is stored for later use.

[0078] Take another basalt flake and place it in ethanol, ensuring the ethanol completely covers the basalt flake. Stir for 15 minutes, filter and dry to remove impurities from the surface of the basalt flake and form a large number of porous structures, obtaining basalt flakes with a layer thickness of about 15 μm to be treated. Take another amide-silane coupling agent and add it to ethanol to prepare an amide-silane coupling agent-ethanol solution with a volume concentration of 2.2%. Add the basalt flakes to be treated, ensuring that the mass of the basalt flakes to be treated is equal to that of the amide-silane coupling agent. Then add 0.3 times the volume of 1M hydrochloric acid solution, stir and react for 3.5 hours, filter and dry to obtain amide-basalt flakes, which are stored for later use.

[0079] Amide-based basalt flakes were added to dimethylformamide, heated to 60±2℃ for 1.75h, and then cooled to 30±2℃ for 0.85h. After the reaction was completed, the mixture was ultrasonically treated for 30h to obtain basalt sheets.

[0080] Test case

[0081] Basalt materials prepared in Examples 1 to 7 and Comparative Examples 1 to 3 were used. 5mm*5mm sheet samples were randomly cut from the samples. The tensile strength of the samples was determined according to the test methods in GB / T 38111-2019, "Classification and Grading of Basalt Fibers," and the breakdown strength was determined according to the test methods in GB / T 6461-2002, "Rating of Specimens and Specimens after Corrosion Testing of Metals and Other Inorganic Coatings on Metal Matrix." The samples were then placed in an alkaline salt solution or a high-temperature environment of 500℃ for 2 hours, and the above properties were tested again after removal. The results are summarized in Table 1 below.

[0082] The alkaline salt solution is a 1L aqueous solution containing 1 mol of equimolar amounts of sodium hydroxide, potassium hydroxide, sodium chloride, and sodium sulfate. After alkaline salt etching, the solution is rinsed with deionized water before measurement. After high-temperature treatment, the solution is cooled to room temperature before measurement.

[0083] Table 1 Performance test results of different basalt material samples

[0084]

[0085] As shown in Table 1 above, before alkali salt or high-temperature treatment, the strength properties of the basalt material samples in Examples 1 to 7 were all higher than those in Comparative Examples 1 to 3. This indicates that the basalt nanosheets in this invention can improve the strength properties of basalt materials through coordination bonding with perovskite. After alkali salt or high-temperature treatment, the decrease in strength properties of the basalt material samples in Examples 1 to 7 was significantly smaller than that in Comparative Examples 1 to 3. This indicates that the basalt nanosheets of this invention can maintain their strength properties more stably in highly corrosive or extremely hot environments. In other words, this invention has a significant and stable effect on modifying the properties of basalt flakes.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A basalt nanosheet, characterized in that, It includes modified basalt flakes and perovskite, wherein the modified basalt flakes and the perovskite are connected by coordination bonding; The ratio of the modified basalt flakes to the perovskite by weight is 1.2-1.5:0.5-0.85; The preparation method of the basalt nanosheets includes the following steps: (1) Preparation of modified basalt flakes; (2) Preparation of perovskite precursor solution; (3) Add the modified basalt flakes to the perovskite precursor solution, heat to 50-65℃ for reaction, then cool to 25-35℃ for reaction, pulverize, dry, and obtain the basalt nanosheets. In step (1), the method for preparing modified basalt flakes includes the following steps: Take cleaned basalt fiber flakes, add them to a 1.5-2.8% volume fraction of amide-silane coupling agent-ethanol solution, add a catalyst, stir to react, filter and dry to obtain the modified basalt flakes. The preparation method of the amide-containing silane coupling agent includes the following steps: Take an aminosilane coupling agent and xylene, mix them evenly, and place them at 5-10℃ for reaction, while adding glacial acetic acid dropwise during the reaction; after the reaction is completed, remove impurities by distillation to obtain the amide-containing silane coupling agent.

2. The basalt nanosheets according to claim 1, characterized in that, The thickness of the basalt flakes is 3-20 μm.

3. The basalt nanosheets according to claim 1, characterized in that, Its thickness is 20-45nm.

4. The basalt nanosheets according to claim 1, characterized in that, The mass ratio of aminosilane coupling agent to xylene is 1:2.5-3.

5. The basalt nanosheets according to claim 1, characterized in that, At the start of the reaction, glacial acetic acid is added dropwise at a constant rate of 0.5-1.5 mL / min, and the total amount of glacial acetic acid added is equal in mass to that of the aminosilane coupling agent.

6. The basalt nanosheets according to claim 1, characterized in that, In step (2), the preparation method of the perovskite precursor solution includes the following steps: Take perovskite, add it to 1.5-3 times its volume of organic solvent, and disperse it by ultrasonication to obtain the perovskite precursor solution.

7. The method for preparing basalt nanosheets according to any one of claims 1, 4-6, characterized in that, In step (3), the reaction time at 50-65℃ is 1-2.5h, and the reaction time at 25-35℃ is 0.5-1.25h.

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